SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a7e102f5094aa7f6aa014d9ec2b5f31f700a42e585bf7f66019511ffc026daf' 
  AND token = 'npORQcMgLATaimW4kieqIBO3Hy9NTk8bFsZ9FSqESfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}